.book-container{
  position: relative;
  .left-container{
    position: fixed;
    left: 0;
    top: 55px;
    bottom: 0;
    width: 280px;
    border-right: 1px solid #ddd;
    background-color: #fafafa;
    display: flex;
    flex-direction: column;
    flex-wrap: nowrap;
    transition: left .25s ease;
    overflow: scroll;
    &::-webkit-scrollbar{
      display: none;
    }
    .deep{
      line-height: 30px;
      padding-left: 10px;
      a{
        color: #666;
      }
    }
    @for $i from 1 through 10 {
      .deep-#{$i} {
        padding-left: 20px * $i + 10px;
      }
    }
  }
  .content-container{
    .article{
      max-width: 960px;
      margin: 0 auto;
      img {
        max-width: 100%;
      }
    }
  }
}